The survival of mankind has always been based on cooperation.
More precisely, it is based on the ascendancy of me and mine over you and yours. Man IS a gregarious animal. He protects himself, he protects his family, he protects his group. (That's why old people weren't sent out into the wilderness, according to the Anthropologists.)
Where there is no threat, Man can accept outsiders as long as they don't break that rule that says that visitors and old socks start to stink after several days. However, altruism was hardly EVER an element of raw survival. The concept of tribalism still rears its ugly head. (See also "divisive politics" - a new name for tribalism.)
In my little comment regarding survival and extinction, "cooperation" in neolithic times meant "hunting parties" and the hunters shared the kills. Everyone contributed. It meant "gathering parties" and everyone carried what amount they could back to the camp. It meant family units where even the kids had specific things that they had to learn to do. Because those families learned to contribute, to have each do a valuable part.
Now please review my earlier comments about "extinction" and tell me where cooperation sneaked into what you read... 'cause I didn't see it in what I wrote. If you don't understand my point, that's on you.
Oh, and DON'T make the statement that we have progressed past that point. No, we haven't, because robberies, gang violence, drug violence, and war haven't vanished from our world.
Violence is like a drug. I remember from the Star Trek (TOS) episode, "A Taste of Armageddon" where Kirk admits that even star-faring humans still have that barbarian in them... but they CAN decide that (paraphrasing), "just for today, we will not kill. We will not kill... today." That is how far we have come. The violence isn't bred out of us but we can resist the urge.
were you drinking when you wrote that?
I would say "sober as a judge" except that these days, even THAT is no longer a good comparison. How about "no alcohol of any kind since about 2012 or 2013" and no non-prescription drugs since I can remember. That even includes MJ, uppers, downers, psychedelics, and other recreational specialties that you won't always find listed in the U.S. Pharmacopeia. Even though I played music on Bourbon Street during my college days, I was only stinking drunk twice in my life, both times before graduating from college. After the second time, I knew I would never get drunk that bad again. And I didn't.
Let's take the more direct answer. I believe I was clear-headed when I wrote that, not under undue influence, and not distracted at the time. If you can't see the truth in what I said, you have taken a bit too much of the Biden lemonade.